Predator-specific inducible morphological defenses of a water flea against two freshwater predators

The expression of inducible morphological defenses in Daphnia in response to a single predator is a well-known phenomenon. However, predator-specific modifications of the same defensive traits as an adaption to different predator regimes is so far only described for Daphnia barbata. It is unknown if this accounts only for this species or if it is a more widespread, general adaptive response in the genus Daphnia. In the present study, we therefore investigated whether a clone of the pond-dwelling species Daphnia similis responds to different predatory invertebrates (Triops cancriformis; Notonecta maculata) with the expression of predator-specific modifications of the same defensive traits. We showed that Triops-exposed individuals express a significantly longer tail-spine, while body width decreased in comparison to control individuals. Additionally, they also expressed inconspicuous defenses, that is, significantly longer spinules on the dorsal ridge. The Notonecta-exposed D. similis showed a significantly longer tail-spine, longer spinules and a larger spinules bearing area on the dorsal ridge than control individuals as well. However, a geometric morphometric analysis of the head shape revealed significant, predator-specific changes. Triops-exposed individuals expressed a flattened head shape with a pronounced dorsal edge, while Notonecta-exposed individuals developed a high and strongly rounded head. Our study describes so far unrecognized inducible defenses of D. similis against two predators in temporary waters. Furthermore, the predator-dependent change in head shape is in concordance with the ‘concept of modality’, which highlights the qualitative aspect of natural selection caused by predators.     

Hydrodynamic Characteristics of Daphnia middendorffiana

Sinking terminal velocities of D. middendorffiana (with and without tail spine) were measured and correlated with morphological parameters and water temperature. The main dimensions of the body showed positive growths rate correlations with the body weight. In turn, negative allometric variation was observed in the tail-spine length. The density of D. middendorffiana was age specific, and decreased as the individual grew. No differences in the sinking terminal velocities and trajectories between individuals with and without tail spine were observed. The observed hydrodynamic characteristics of D. middendorffiana were simulated by means of a model based on equivalent ellipsoids and spheres. The analysis showed that the effects of shape and the body projections are negligible on the sinking rates of D. middendorffiana.     

The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda

The phylogenetic position of aglaspidids, a problematic group of Lower Palaeozoic arthropods of undetermined affinities, is re‐examined in the context of the major Cambrian and Ordovician lamellipedian arthropod groups. A cladistic analysis of ten genera of aglaspidids sensu stricto, six aglaspidid‐like arthropods and 42 Palaeozoic arthropod taxa indicates that Xenopoda, Cheloniellida, Aglaspidida sensu lato and Trilobitomorpha form a clade (Artiopoda Hou and Bergström, 1997 ) nested within the mandibulate stem‐lineage, thus discarding previous interpretations of these taxa as part 'of the chelicerate stem‐group (Arachnomorpha Heider, 1913 ). The results confirm an aglaspidid identity for several recently described arthropods, including Quasimodaspis brentsae, Tremaglaspis unite, Chlupacaris dubia, Australaglaspis stonyensis and an unnamed Ordovician Chinese arthropod. The problematic Bohemian arthropod Kodymirus vagans was recovered as sister taxon to Beckwithia typa, and both form a small clade that falls outside Aglaspidida sensu stricto, thus discarding eurypterid affinities for the former. The analysis does not support the phylogenetic position of Kwanyinaspis maotianshanensis at the base of Conciliterga as proposed in recent studies, but rather occupies a basal position within Aglaspidida sensu lato. The results indicate a close association of aglaspidid arthropods with xenopods (i.e. Emeraldella and Sidneyia) and cheloniellids (e.g. Cheloniellon, Duslia); the new clade “Vicissicaudata” is proposed to encompass these arthropods, which are characterized by a differentiated posterior region. The phylogenetic position of aglaspidid arthropods makes them good outgroup candidates for analysing the internal relationships within the groups that form Trilobitomorpha. This work provides a much clearer picture of the phylogenetic relationships among Lower Palaeozoic lamellipedians.     

Three independent genetic systems that control initiation of a fungal fruiting body

Summary The initiation of monokaryotic fruiting in the basidiomycetous fungus Schizophyllum commune has been observed to occur spontaneously, in response to biochemical substances, and following mechanical injury. The responses to these three stimuli are genetically separable and under polygenic control.Paper #2259 from the Laboratory of Genetics, University of Wisconsin, Madison, Wisconsin 53706Supported in part by the College of Agriculture and Life Science, University of Wisconsin and NIH Predoctoral Training Grant #GM 07133 to the Laboratory of Genetics, University of WisconsinSupported in part by the College of Agriculture and Life Sciences, University of Wisconsin and by grant PCM77-05581 from the National Science Foundation     

Patterns in the species composition of fish assemblages among Wisconsin streams

Synopsis To better understand patterns of fish assemblage composition in Wisconsin streams in relation to major environmental gradients, I carried out multivariate direct gradient analysis (canonical correspondence analysis) of two large independent datasets on fish species abundance in Wisconsin streams. Analysis of the two datasets yielded similar results, suggesting that observed patterns and relationships were real. Stream sites were distributed along fish species-environment gradients, but segregation into distinct stream temperature and geographic groups was also evident. The strongest gradient in both datasets was related to summer water temperature patterns, and encompassed a transition from small, coldwater streams dominated by salmonids, cottids, certain cyprinids, and few other species, to both small and large, warmwater streams dominated by a high diversity of different cyprinids, catostomids, ictalurids, centrarchids, and percids. A second gradient in both datasets was complex but largely geographic. Within it, sites from each of the four ecoregions that occupy Wisconsin formed fairly discrete groups. The strongest differences were between sites in the two southern Wisconsin ecoregions, the Driftless Area and the Southeastern Wisconsin Till Plains, that were dominated by certain cyprinids, ictalurids, and centrarchids, and sites in the two northern Wisconsin ecoregions, the North Central Hardwood Forests and the Northern Lakes and Forests, that were dominated by a different set of cyprinids and ictalurids, plus some petromyzontids, salmonids, catostomids, and percids. Sites from the Driftless Area that were mostly higher-gradient (steep stream slope) and had many riffle-dwelling species could also be distinguished from sites in the Southeastern Wisconsin Till Plains that were mostly lower-gradient and had many pool-dwelling species. The patterns of fish assemblage composition among sites and the associated fish species-environment relationships that were revealed by the analyses provided a framework for developing an ecologically meaningful hierarchical classification of Wisconsin stream sites based on stream thermal regime, ecoregion, stream size, and stream gradient.     

Hematozoa of wild turkeys from the midwestern United States: translocation of wild turkeys and its potential role in the introduction of Plasmodium kempi

Twenty-three of 310 blood samples taken from live-trapped eastern wild turkeys (Meleagris gallopavo silvestris) from Missouri (USA), and hunter-killed birds from Wisconsin, North Dakota and Minnesota (USA), and inoculated into domestic broad-breasted-white turkey poults were positive for two species of Plasmodium. Twenty-one of the positive samples were infected with P. (Novyella) kempi, and two samples from Wisconsin were infected with P. (Giovannolaia) lophurae. Twenty percent of 310 blood smears were positive for Haemoproteus melagridis, while only 3% were infected with Leucocytozoon smithi. A statistically higher prevalence of Plasmodium spp. from 1983 to 1984 was observed in Wisconsin, and in the samples from Minnesota when compared with both Missouri and Wisconsin. Turkeys from Wisconsin and Minnesota had both a statistically higher prevalence and mean intensity of H. meleagridis than birds from Missouri. Evidence indicates that P. kempi has been introduced into other states along with the vertebrate hosts. It is suggested that greater care should be exercised when translocated wild turkeys are introduced into areas where there are other endangered or threatened avian species.     

Response of stomatal resistance and photosynthesis to night temperature in Populus deltoides

Summary Ramets from stem cuttings of three populations of Populus deltoides Bartr. from Wisconsin, Illinois, and Louisiana representing a latitudinal gradient were grown in pots outdoors at Urbana, Illinois and brought indoors for growth chamber studies. Leaf resistance and photosynthetic response to low night temperatures of 4° and 10° C were determined relative to 20° C controls for plants measured over one growing season. Plants from Louisiana, where nights are warm, reacted to cool nights of 4° and 10° C by opening their stomata slower upon illumination the following day than those from farther north where nights are cooler. The optimum night temperature for rate of opening was lower in the Wisconsin population than in populations from farther south. The Wisconsin population showed more ideal homeostasis of photosynthesis at different temperatures than the southern population which exhibited greater plasticity. No seasonal differences in these relationships were apparent other than at the time of leaf senescence.As plants approached senescence, which occurred earliest in the Wisconsin population, leaf resistance increased and photosynthesis declined, but stomata still retained their functional ability to respond to changes in night temperature. The change in leaf resistance, noted in the Wisconsin population, was related more to closure of lower-leaf surface stomata than upper. Only the Louisiana population had significantly more stomata on the lower than upper leaf surface.     

Long-distance dispersal of the gypsy moth (Lepidoptera: Lymantriidae) facilitated its initial invasion of Wisconsin

Gypsy moth (Lymantria dispar L.) spread is dominated by stratified dispersal, and, although spread rates are variable in space and time, the gypsy moth has invaded Wisconsin at a consistently higher rate than in other regions. Allee effects, which act on low-density populations ahead of the moving population that contribute to gypsy moth spread, have also been observed to be consistently weaker in Wisconsin. Because a major cause of an Allee effect in the gypsy moth is mate-finding failure at low densities, supplementing low-density populations with immigrants that arrive through dispersal may facilitate establishment and consequent spread. We used local indicator of spatial autocorrelation methods to examine space-time gypsy moth monitoring data from 1996 to 2006 and identify isolated, low-density colonies that arrived through dispersal. We measured the distance of these colonies from the moving population front to show that long-distance dispersal was markedly present in earlier years when Wisconsin was still mainly uninfested. Recently, however, immigrants arriving through long-distance dispersal may no longer be detected because instead of invading uninfested areas, they are now supplementing high-density colonies. In contrast, we observed no temporal pattern in the distance between low-density colonies and the population front in West Virginia and Virginia. We submit that long-distance dispersal, perhaps facilitated through meteorological mechanisms, played an important role in the spread dynamics of the initial Wisconsin gypsy moth invasion, but it currently plays a lesser role because the portion of Wisconsin most susceptible to long-distance immigrants from alternate sources is now heavily infested.     

Monokaryotic fruiting in Schizophyllum commune: Genetic control of the response to mechanical injury

Summary Monokaryotic fruiting is used as a tool to study mushroom development and differentiation in Schizophyllum commune. This paper reports data which further elucidate the genetic control of the monokaryotic fruiting response to mechanical injury. Models relating the various genes implicated in monokaryotic fruiting body production are proposed and evaluated on their ability to explain the observed data. A minimum estimate is made of the number of genes involved in the initiation of monokaryotic fruiting in response to mechanical injury.Paper # 2260 from the Laboratory of Genetics, University of Wisconsin, Madison. Wisconsin 53706, USASupported in part by the College of Agriculture and Life Sciences, University of Wisconsin and by NIH Predoctoral Training Grant # GM 07133 to the Laboratory of Genetics, University of Wisconsin     

Serologic evidence of arboviral infections in white-tailed deer from central Wisconsin

A survey conducted during 1979-1980 on white-tailed deer (Odocoileus virginianus) in central Wisconsin revealed serological evidence of infection by selected arboviruses. Among sera from 41 deer, antibody was detected for Jamestown Canyon virus (56%) and Bunyamwera group virus (80%), demonstrating their continuing endemic activity. Antibody for La Crosse virus, not found previously in sera from deer in central Wisconsin, also was detected (5%) in this study.     

Reduced Function of a Phenylacetate-Oxidizing Cytochrome P450 Caused Strong Genetic Improvement in Early Phylogeny of Penicillin-Producing Strains

The single-copy pahA gene from Penicillium chrysogenum encodes a phenylacetate 2-hydroxylase that catalyzes the first step of phenylacetate catabolism, an oxidative route that decreases the precursor availability for penicillin G biosynthesis. PahA protein is homologous to cytochrome P450 monooxygenases involved in the detoxification of xenobiotic compounds, with 84% identity to the Aspergillus nidulans homologue PhacA. Expression level of pahA displays an inverse correlation with the penicillin productivity of the strain and is subject to induction by phenylacetic acid. Gene expression studies have revealed a reduced oxidative activity of the protein encoded by pahA genes from penicillin-overproducing strains of P. chrysogenum compared to the activity conferred by phacA of A. nidulans. Sequencing and expression of wild-type pahA from P. chrysogenum NRRL 1951 revealed that an L181F mutation was responsible for the reduced function in present industrial strains. The mutation has been tracked down to Wisconsin 49-133, a mutant obtained at the Department of Botany of the University of Wisconsin in 1949, at the beginning of the development of the Wisconsin family of strains.     

Correlation of (Ordovician, Mohawkian) K-bentonites in the upper Mississippi valley using apatite chemistry: implications for stratigraphic interpretation of the mixed carbonate-siliciclastic Decorah Formation

Four Ordovician K-bentonites have been chemically fingerprinted using trace element content of apatite phenocrysts contained within the altered ash layers. Trace element analysis was performed using electron microprobe on individual crystals. The bentonites include the Deicke, Millbrig, Elkport, and Dickeyville beds. These beds lie within the Decorah Formation of the northern Mississippi Valley outcrop area. All four K-bentonite beds are believed to have a Taconic source whereas volcanic ash was transported by wind and deposited in the Ordovician North America epeiric sea.

The Decorah is a marine unit, shaly to the north and west and carbonate-rich to the south and east. Thirteen K-bentonite samples were collected from six localities. Only one locality (Dickeyville, WI) contains all four beds in succession. One hundred seventy-one apatite crystals were handpicked and analyzed for major, minor and trace elements using an electron microprobe. Each crystal was analyzed at three to six separate spots to ascertain compositional variation. The most discriminating and diagnostic elements were Mg and Mn; plotting Mg vs. Mn content produces data clusters characteristic for each K-bentonite. Clusters show only minimal change between localities, allowing individual K-bentonites to be identified and used for stratigraphic correlation.

Time slices provided by the K-bentonite horizons show that the Decorah Formation is composed of reciprocal wedges (stratigraphic sequences) of shale and carbonate. Shale was deposited in deeper water within the Hollandale Embayment but pinched out southeastward onto the flank of the Wisconsin Dome. Carbonates were formed largely in shoal water on the arch, prograding northwestward and shaling out downramp into the embayment.     

Corky Root of Lettuce Caused by Strains of a Gram-Negative Bacterium from Muck Soils of Florida, New York, and Wisconsin

Slow-growing bacteria similar to the bacterium causing lettuce corky root (CR) in California (strain CA1) were isolated from muck soils of Florida, New York, and Wisconsin, using lettuce seedlings as bait. All strains were tested for reaction with polyclonal antibodies produced against strain CA1 and for pathogenicity on CR-susceptible (Salinas) and CR-resistant (Green Lake) lettuce cultivars in a greenhouse. Five strains from Florida, three from New York, and three from Wisconsin induced severe CR symptoms on Salinas and mild symptoms on Green Lake. All strains were gram-negative, aerobic, oxidase positive, and catalase positive and reduced nitrate to ammonia. Whole-cell fatty acid compositions were similar for all strains and resembled that of Pseudomonas paucimobilis. Since this fatty acid pattern is unique, it is suggested that CR of lettuce is caused by strains of the same bacterium in Florida, New York, Wisconsin, and California.     

Hydrologic and biogeochemical controls on trace element export from northern Wisconsin wetlands

Wetlands play an important role in determining the water quality of streams and are generally considered to act as a sink for many reactive species. However, retention of chemical constituents varies seasonally and is affected by hydrologic and biogeochemical processes including water source, mineral weathering, DOC and SPM cycling, redox status, precipitation/dissolution/adsorption, and seasonal events. Relatively little is known about the influence of these factors on trace element cycling in wetland-influenced streams. To explore the role of wetlands with respect to the retention/release of trace elements to streams, we examined temporal and spatial patterns of concentrations of a large suite of trace elements (via ICP-MS) and geochemical drivers in five streams and wetland rivulets draining natural wetlands in a northern Wisconsin watershed as well as in their groundwater sources (terrestrial recharge, lake recharge, and older lake recharge). We performed principal components analyses of the concentrations of elements and their geochemical drivers in both the streams and rivulets to assist in the identification of factors regulating trace element concentrations. Variation in trace and major element concentrations among the streams was strongly related to the proportion of terrestrial recharge contributing to the stream. A dominant influence of water source on rivulet chemistry was supported by association of groundwater-sourced elements (Ba, Ca, Cs, Mg, Na, Si, Sr) with the primary statistical factor. DOC appeared in the first principal component factor for the streams and in the second factor for the rivulets. Strong correlations of Al, Cd, Ce, Cu, La, Pb, Ti, and Zn with DOC supported the important influence of DOC on trace metal cycling. A number of elements in the rivulets (Al, La, Pb, Ti) and streams (Al, Ce, Cr, Cu, La, Pb, Ti, Zn) had a significant particulate cycle. Redox cycling and precipitation/dissolution reactions involving Fe and Mn likely impacted Cu and Mo as evidenced by the low levels in the rivulets. Variance in Fe, Mn and the metal oxy-anions was associated with factors related to redox cycling and adsorption reactions in the wetland sediments. In streams, DOC and metals with a high affinity for DOC were associated with a factor which also included negative loadings for groundwater-sourced elements, reflecting the importance of seasonal hydrologic events which flush DOC and metals from wetland sediments and dilute groundwater sourced metals. Redox processes were of secondary importance in the streams but of primary significance in the rivulets, documenting the importance of anoxic conditions in wetland sediments on groundwater en route to the stream.     

Uptake of phenylacetic acid by two strains of Penicillium chrysogenum

Uptake of phenylacetic acid, the side-chain precursor of benzylpenicillin, was studied in Penicillium chrysogenum Wisconsin 54-1255 and in a strain yielding high levels of penicillin. In penicillin fermentations with the high-yielding strain, 100% recovery of phenylacetic acid in benzylpenicillin was found, whereas in the Wisconsin strain only 17% of the supplied phenylacetic acid was incorporated into benzylpenicillin while the rest was metabolized. Accumulation of total phenylacetic acid-derived carbon in the cells was nonsaturable in both strains at high external concentrations of phenylacetic acid (250-3500 microM), and in the high-yielding strain at low phenylacetic acid concentrations (2. 8-100 microM), indicating that phenylacetic acid enters the cells by simple diffusion, as concluded earlier for P. chrysogenum by other authors. However, at low external concentrations of phenylacetic acid saturable accumulation appeared in the Wisconsin strain. HPLC-analyses of cell extracts from the Wisconsin strain showed that phenylacetic acid was metabolized immediately after entry into the cells and different [14C]-labeled metabolites were detected in the cells. Up to approximately 50% of the accumulated phenylacetic acid was metabolized during the transport-assay period, the conversion having an impact on the uptake experiments. Nevertheless, accumulation of free unchanged phenylacetic acid in the cells showed saturation kinetics, suggesting the possible involvement of a high-affinity carrier in uptake of phenylacetic acid in P. chrysogenum Wisconsin 54-1255. At high concentrations of phenylacetic acid, contribution to uptake by this carrier is minor in comparison to simple diffusion and therefore, of no importance in the industrial production of penicillin.     

Absorption microphotometry of irregular-shaped objects

Summary A new microphotometric method (mainly for the evaluation of microchemical color reactions) which uses measurements at two wave lengths (developed byOrnstein and, independently, by the author) is presented in a form which greatly reduces the computational labor (for an illustration, see Table 3).Contribution from the Program in Cytology, Department of Botany, University of Wisconsin, Madison, supported in part by grants to Dr.C. Leonard huskins from the Research Committee of the Graduate School with funds supplied by the Wisconsin Alumni Research Foundation.     

The cuticle of the enigmatic arthropod Phytophilaspis and biomineralization in Cambrian arthropods

Lin, J.‐P., Ivantsov, A.Y. & Briggs, D.E.G. 2011: The cuticle of the enigmatic arthropod Phytophilaspis and biomineralization in Cambrian arthropods. Lethaia, Vol. 44, pp. 344–349. Many non‐trilobite arthropods occur in Cambrian Burgess Shale‐type (BST) biotas, but most of these are preserved in fine‐grained siliciclastics. Only one important occurrence of Cambrian non‐trilobite arthropods, the Sinsk biota (lower Sinsk Formation, Botomian) from the Siberian Platform, has been discovered in carbonates. The chemical compositions of samples of the enigmatic arthropod Phytophilaspis pergamena Ivantsov, 1999 and the co‐occurring trilobite Jakutus primigenius Ivantsov in Ponomarenko, 2005 from this deposit were analysed. The cuticle of P. pergamena is composed of mainly calcium phosphate and differs from the cuticle of J. primigenius, which contains only calcium carbonate. Phosphatized cuticles are rare among large Cambrian arthropods, except for aglaspidids and a few trilobites. Based on recent phylogenetic studies, phosphatization of arthropod cuticle is likely to have evolved several times. □arthropod cuticle, Burgess Shale‐type preservation, fossil‐diagenesis, phosphatization.     

A tetrazolium method for distinguishing between cultured human fibroblasts having either normal or deficient levels of glucose-6-phosphate dehydrogenase

A histochemical staining method for glucose-6-phosphate dehydrogenase is described which readily distinguishes in a mixed population cultured fibroblasts having normal and deficient levels of the enzyme. Applications of the technique are discussed.Paper # 1112 from the Laboratory of Genetics, University of Wisconsin, Madison, Wisconsin. This work was supported by the National Institutes of Health (Grants # GM-08217, # GM-398, and # GM-06983).Predoctoral Fellow of the Pan American Union and of the American Association of University Women.     

Relationship between foliar composition of red-pine and jack-pine seedlings and vulnerability to Lophodermium needle-cast disease

Summary The Mn and Al content of needles from two-year-old jack pine (Pinus banksiana) seedlings was found to be more than twice that of red pine (Pinus resinosa). It is speculated that the high Mn and Al content of jack pine seedlings may impart some degree of resistance to needle cast disease caused byLophodermium pinastri. Contribution from the Soils Dept., Univ. of Wis., Madison, in cooperation with and supported in part by the Wisconsin Dept. of Natural Resources. Publication approved by the Director of the Wisconsin Agricultural Experiment Station.     

Biochemical genetics of macaques. I. 6-phosphogluconate dehydrogenase polymorphisms in Macaca mulatta and Macaca speciosa

Starch gel electrophoresis of erythrocytes from 1812 Macaca mulatta has unequivocally demonstrated that the 6-phosphogluconate dehydrogenase (6PGD) isozymes are controlled by two autosomal codominant alleles. Limited data on erythrocytes from 89 Macaca speciosa were also consistent with autosomal codominance.This work was supported in part by NIH Grants HD 07835 (WHS) and RR-00167 (Wisconsin Regional Primate Research Center) and by the Research Committee of the UW Graduate School (Project No. 170207).Paper No. 2146 of the Laboratory of Genetics, and Publication No. 16-045 of The Wisconsin Regional Primate Research Center.